Fluorinated Amino Acids Probe Peptide-Membrane Interactions

In a recent Biochemistry article, the Marsh group at the University of Michigan continues their work with fluorinated antimicrobial peptides (doi: 10.1021/bi100605e). Though these fluorines are not used in fluorous separations, we’ve enjoyed following the group’s work here in F-Blog for some time. A broad theme in the work is that replacing regular amino acids with fluorinated analogs, such as hexafluoroleucine, improves the stability of the peptide while retaining the desired antimicrobial properties. See our posts “Fluorous Amino Acids in Peptides“, “Fluorinated Amino Acid Synthesis“, and “Fluorine in Peptides” for additional background information.

In this paper, the researchers incorporate trifluoroethylglycine into the antimicrobial peptide MSI-78 to act as a probe. As the peptides interact with lipid membranes, the change in the chemical environment of the trifluoro group can be monitored by 19F NMR.

The authors report several advantages to this approach, including the high sensitivity and lack of background noise (fluorine is not naturally found in peptides) . Additionally, all molecules are in solution, allowing for dynamic information about the peptide-membrane interaction to be obtained. Future efforts aim to use this technique for in vivo studies of peptide-membrane interactions. We look forward to reading about them.